diff --git a/src/librustc_mir/dataflow/drop_flag_effects.rs b/src/librustc_mir/dataflow/drop_flag_effects.rs index e35bd34c40bd..7ef9cc6fc3f4 100644 --- a/src/librustc_mir/dataflow/drop_flag_effects.rs +++ b/src/librustc_mir/dataflow/drop_flag_effects.rs @@ -231,8 +231,13 @@ pub(crate) fn drop_flag_effects_for_location<'a, 'gcx, 'tcx, F>( } } } + mir::StatementKind::StorageDead(local) => { + on_lookup_result_bits(tcx, mir, move_data, + move_data.rev_lookup.find(&mir::Lvalue::Local(local)), + |mpi| callback(mpi, DropFlagState::Absent)) + + } mir::StatementKind::StorageLive(_) | - mir::StatementKind::StorageDead(_) | mir::StatementKind::InlineAsm { .. } | mir::StatementKind::EndRegion(_) | mir::StatementKind::Validate(..) | diff --git a/src/librustc_mir/dataflow/impls/mod.rs b/src/librustc_mir/dataflow/impls/mod.rs index dad96dc3a6ff..524f8ffed83f 100644 --- a/src/librustc_mir/dataflow/impls/mod.rs +++ b/src/librustc_mir/dataflow/impls/mod.rs @@ -456,14 +456,21 @@ impl<'a, 'gcx, 'tcx> BitDenotation for MovingOutStatements<'a, 'gcx, 'tcx> { let path_map = &move_data.path_map; let rev_lookup = &move_data.rev_lookup; - debug!("stmt {:?} at loc {:?} moves out of move_indexes {:?}", - stmt, location, &loc_map[location]); - for move_index in &loc_map[location] { - // Every path deinitialized by a *particular move* - // has corresponding bit, "gen'ed" (i.e. set) - // here, in dataflow vector - zero_to_one(sets.gen_set.words_mut(), *move_index); + match stmt.kind { + // skip move out for StorageDead + mir::StatementKind::StorageDead(_) => {} + _ => { + debug!("stmt {:?} at loc {:?} moves out of move_indexes {:?}", + stmt, location, &loc_map[location]); + for move_index in &loc_map[location] { + // Every path deinitialized by a *particular move* + // has corresponding bit, "gen'ed" (i.e. set) + // here, in dataflow vector + zero_to_one(sets.gen_set.words_mut(), *move_index); + } + } } + let bits_per_block = self.bits_per_block(); match stmt.kind { mir::StatementKind::SetDiscriminant { .. } => { diff --git a/src/librustc_mir/dataflow/move_paths/builder.rs b/src/librustc_mir/dataflow/move_paths/builder.rs index f333dd4d2a17..a0212de605ee 100644 --- a/src/librustc_mir/dataflow/move_paths/builder.rs +++ b/src/librustc_mir/dataflow/move_paths/builder.rs @@ -250,8 +250,10 @@ impl<'b, 'a, 'gcx, 'tcx> Gatherer<'b, 'a, 'gcx, 'tcx> { } self.gather_rvalue(rval); } - StatementKind::StorageLive(_) | - StatementKind::StorageDead(_) => {} + StatementKind::StorageLive(_) => {} + StatementKind::StorageDead(local) => { + self.gather_move(&Lvalue::Local(local), true); + } StatementKind::SetDiscriminant{ .. } => { span_bug!(stmt.source_info.span, "SetDiscriminant should not exist during borrowck"); @@ -309,7 +311,7 @@ impl<'b, 'a, 'gcx, 'tcx> Gatherer<'b, 'a, 'gcx, 'tcx> { TerminatorKind::Unreachable => { } TerminatorKind::Return => { - self.gather_move(&Lvalue::Local(RETURN_POINTER)); + self.gather_move(&Lvalue::Local(RETURN_POINTER), false); } TerminatorKind::Assert { .. } | @@ -322,7 +324,7 @@ impl<'b, 'a, 'gcx, 'tcx> Gatherer<'b, 'a, 'gcx, 'tcx> { } TerminatorKind::Drop { ref location, target: _, unwind: _ } => { - self.gather_move(location); + self.gather_move(location, false); } TerminatorKind::DropAndReplace { ref location, ref value, .. } => { self.create_move_path(location); @@ -344,19 +346,19 @@ impl<'b, 'a, 'gcx, 'tcx> Gatherer<'b, 'a, 'gcx, 'tcx> { match *operand { Operand::Constant(..) => {} // not-a-move Operand::Consume(ref lval) => { // a move - self.gather_move(lval); + self.gather_move(lval, false); } } } - fn gather_move(&mut self, lval: &Lvalue<'tcx>) { + fn gather_move(&mut self, lval: &Lvalue<'tcx>, force: bool) { debug!("gather_move({:?}, {:?})", self.loc, lval); let tcx = self.builder.tcx; let gcx = tcx.global_tcx(); let lv_ty = lval.ty(self.builder.mir, tcx).to_ty(tcx); let erased_ty = gcx.lift(&tcx.erase_regions(&lv_ty)).unwrap(); - if !erased_ty.moves_by_default(gcx, self.builder.param_env, DUMMY_SP) { + if !force && !erased_ty.moves_by_default(gcx, self.builder.param_env, DUMMY_SP) { debug!("gather_move({:?}, {:?}) - {:?} is Copy. skipping", self.loc, lval, lv_ty); return } diff --git a/src/test/compile-fail/borrowck/borrowck-storage-dead.rs b/src/test/compile-fail/borrowck/borrowck-storage-dead.rs new file mode 100644 index 000000000000..5ef502acd811 --- /dev/null +++ b/src/test/compile-fail/borrowck/borrowck-storage-dead.rs @@ -0,0 +1,30 @@ +// Copyright 2012 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// compile-flags: -Z emit-end-regions -Z borrowck-mir + +fn ok() { + loop { + let _x = 1; + } +} + +fn fail() { + loop { + let x: i32; + let _ = x + 1; //~ERROR (Ast) [E0381] + //~^ ERROR (Mir) [E0381] + } +} + +fn main() { + ok(); + fail(); +}